The installment features two of the series’ most beloved couples – Rachel (Lea Michele) and Finn (Cory Monteith) as well as Kurt (Chris Colfer) and Blaine (Darren Criss) -- taking the next step in their committed, long-term relationships: sex.

“Having watched it myself, I think it was a really well done episode and I think it handled a lot of sensitive topics very maturely,” Monteith tells The Hollywood Reporter.

Tuesday’s Glee features both nods to safe sex and teen pregnancy when Finn turns to Puck (Mark Salling) for advice about condoms and instead gets a funny yet poignant line that references Puck and Quinn’s (Dianna Agron) Season 1 pregnancy story line.

“Puck says, ‘I don’t use ’em and it works for me 99 percent of the time,’ ” Monteith says. “I think the show has a certain level of responsibility to advocate for teenagers making better choices. To see a scene that implies that teenagers have the opportunity to make the right choices in situations like that is pretty cool.”

With Finn already having lost his virginity in a Season 2 story line in which he and Santana (Naya Rivera) did the deed in a bid for the school quarterback to up his cool factor, Monteith says he approached Finn and Rachel’s intimate story line as if it were the character’s first time.

“Tina (Jenna Ushkowitz) has a speech [in the episode] that I liked about her first time and how it was enjoyable because her first time was with someone she loved,” he says. “That’s very much Finn's experience because it’s an emotionally committed relationship for him. In a sense, Santana is water under the bridge.”

While there may be a red flag or two in the episode indicating that Finn may not know Rachel as well as he thinks he does – he serves a vegetarian Rachel dinner that includes meat on the menu -- ultimately Monteith says the couple’s sexually active status can only mean good things for the duo that has certainly seen its share of ups and downs.

“I think it's only going to strengthen it because they have such a history,” he says. “I think they both, from what I can see from what's coming down the pike from writers, they are both very much committed and symbiotic.”

“Finn is smart like a fox; he's certainly come a long way in the last year and a half but is still very young and I think forgetting that his girlfriend was a vegetarian was something Finn would do just because he’s Finn, not because he doesn’t know Rachel,” he adds.”

While Michele told THR in October that Finn is “deciding if he’s an Ohio boy or if he’s going to come to New York,” Monteith says Rachel will continue to stand by Finn’s side after he receives some bad news about his post-high school plans in Tuesday’s episode from a football recruiter visiting McKinley.

“The romantic relationship will continue and she’s very much a support system for him,” Monteith says. “She's very much there for him and she’s not taking any of his shortcomings personally and not sweating him so he can get through what he needs to get through. It's a healthy relationship.”

As for Finn’s uncertain future, Monteith says Finn could consider any number of options, including working at Burt’s (Mike O’Malley) garage, exploring other colleges with football programs or putting a greater emphasis on his performance in New Directions.

Meanwhile, Monteith is very pleased with the way Tuesday’s episode turned out and singles out a Kurt-Blaine scene as his most memorable of the episode.

“Darren Criss and Chris Colfer have a parking lot scene and the way that they handled it was really brilliant; it was very mature and I loved it,” he says of the scene in which Kurt rejects a tipsy Blaine’s advances.

“I'm a huge fan of this episode and it's very personal to me,” he says. “I feel like it's a good accomplishment for the show. It's one of the best [episodes] so far.”